Exploring Creation with Marine Biology Module 1 - The Oceans of Our Planet

how much of the world is covered by oceans

71%

which hemisphere has more ocean area

the Southern Hemisphere (80%)

how many large ocean basins are on earth

4

what are the four major ocean basins

the Pacific, Atlantic, Indian, and Arctic Ocean basins

which ocean is not a true ocean basin

the Southern Ocean

which ocean basin is the largest and deepest

Pacific Ocean basin

what are the four layers of the earth

crust, mantle, outer core, and inner core

what is the core of the earth primarily made of

iron

which layer of the earth has the highest pressure

the inner core

which layer of the earth is made of plastic rock

the mantle

plastic rock

a slow-moving substance that is in a constantly fluctuating state between liquid-like material and solid-like material

which of the layers of the earth is the thinnest

the crust

what are the two types of the earth’s crusts

oceanic and continental crusts

oceanic crust

the denser part of the earth covered with ocean and is composed mainly of basalt and is 5 km thick

continental crust

the less dense, lighter colored part of the earth made of granite about 20-50 km thick

basalt

solidified lava with a darkened color

continental drift

the belief that all the continents were originally part of one supercontinent that broke apart and moved away from each other

Pangaea

the name of the believed supercontinent

who came up with the hypothesis of continental drift

Alfred Wegner

plate tectonics

a process involving the movement of large plates on the earth’s mantle based on the idea that the crust is divided into large, irregular plates that float on the mantle

mid-ocean ridge systems

continuous chains of underwater volcanic mountains encompassing the earth where the edges of plates meet; sometimes form islands

trench systems

systems of deep depressions (trenches) where the edges of plates meet; most commonly located in the Pacific Ocean basin

which system is more likely to have earthquakes

ridges

which system is more likely to have active volcanoes

trenches

magnetic anomalies

magnetic particles inside of ridges pointing in the “wrong” direction, suggesting that bands of igneous rock on the ocean floor were formed from molten rock at different times in history

rift

a separation, or crack in the crust, between two plates

magma

melted rock that rises out of the mantle

seafloor spreading

the process that creates new seafloor as plates move away from each other at mid-ocean ridges

catastrophic plate tectonics

rapid plate movement during catastrophic events

subduction

the downward movement of a plate into the earth’s mantle when two plates collide

what happens to a plate when it enters the mantle

it begins to break apart from the extreme heat and pressure, eventually melting and rising back up to form volcanoes

which one sinks below the other during a collision: oceanic plate or continental plate

the oceanic plate sinks, creating a trench and forming mountain ranges from volcanoes

which one sinks below the other during a collision: oceanic plate or oceanic plate

one of the oceanic plates will sink, forming a trench and volcanoes

which one sinks below the other during a collision: continental plate or continental plate

neither; they push against each other to fold the rock over, forming large mountain ranges

shear boundary

a type of plate boundary that may occur when two plates slide past each other without forming or destroying plate material; results in a fault

why do earthquakes occur after two plates in a shear boundary move

there is too much friction between the plates, so when it removes the plates slide all at once, resulting in an earthquake formed from the built up pressure

continental shelf

the gently-sloped, shallow section of the edge of a continent that extends from the shore to the point where the slope steepens; contains the richest diversity of marine life

what percentage of the ocean’s surface area is continental shelf

about 8%

shelf break

the outer edge of the shelf where the bottom begins to become steeper, occurring at a depth of 120-200 meters

continental slope

the steeper section of a continental edge extending seaward from the continental shelf

continental rise

the gently sloping area at the base of the continental slope; has the most sediment buildup

abyssal plain

the flat seafloor area at the bottom that gently slopes upward toward the mid-ocean ridges

hydrogen bond

a weak bond resulting from the attraction between oppositely charged ends of a water molecule

surface tension

a flexible skin at the surface of water caused by hydrogen bonding

specific heat

the amount of energy required to raise the temperature of 1 gram of a substance by 1℃

solvent

a substance that can dissolve other substances

salts

a class of molecules made of particles that have opposite electrical charges

ions

electrically charged particles in a salt

salinity

the total amount of salt dissolved in a solvent, measured in parts per thousand (‰)

what ion has the highest concentration in seawater

chloride

experiment control

a sample that provides a baseline for an experiment

what is the typical temperature range

-3 - 40 degrees Celsius

thermocline

a zone of transition separating two layers of water with distinctly different temperatures and densities

why is the ocean blue

the ocean is the most transparent to blue light, making it the most prominent color; it also reflects the color of the sky

Coriolis effect

the way the rotation of the earth bends the path of winds and resulting sea currents

trade winds

the most consistent winds on earth that bend west and approach the equator at a 45 degree angle

westerlies

winds near the surface of the earth that bend opposite to the trade winds, traveling away from the equator; more variable due to land interruptions

polar easterlies

the northernmost and southernmost winds that are the most variable winds of all, curving in the same direction as the trade winds since they move towards the equator

gyres

large, mostly circular systems of surface currents driven by the wind; circulates the water to keep the temperatures from becoming too extreme

tides

regular ocean water movement that is caused by gravitational pull of the sun and moon on both sides of the earth

spring tide

a time of largest tidal range due to gravitational pull of the aligned sun and full/new moon

neap tide

a time of smallest tidal range due to the quarter moon and sun being located at right angles to each other

how often do solar tides occur

twice a day

how often do lunar tides occur

once every 24 hours and 50 minutes

surface layer

the top layer of the ocean that is about 100-200 meters thick and is subject to wind, waves, and currents, resulting in consistent mixing

thermocline (layer)

a zone about 200-1500 meters deep where water temperature drops rapidly, found in the open ocean away from continental shelf areas

deep layer

the layer of colder, denser water located beneath the thermocline

water column

a group of distinct water layers (surface, thermocline, deep) that are only stirred up by strong winds or storms

low-stability water column

a situation in which the layers of a water column have similar densities, resulting in denser and cooler surface water

overturn

the process in which denser surface water sinks down and displaces the less-dense water below